Weitere Artikel dieser Ausgabe durch Wischen aufrufen
We address the problem of superimposed trainings- (STs-) based linearly time-varying (LTV) channel estimation and symbol detection for orthogonal frequency-division multiplexing access (OFDMA) systems at the uplink receiver. The LTV channel coefficients are modeled by truncated discrete Fourier bases (DFBs). By judiciously designing the superimposed pilot symbols, we estimate the LTV channel transfer functions over the whole frequency band by using a weighted average procedure, thereby providing validity for adaptive resource allocation. We also present a performance analysis of the channel estimation approach to derive a closed-form expression for the channel estimation variances. In addition, an iterative symbol detector is presented to mitigate the superimposed training effects on information sequence recovery. By the iterative mitigation procedure, the demodulator achieves a considerable gain in signal-interference ratio and exhibits a nearly indistinguishable symbol error rate (SER) performance from that of frequency-division multiplexed trainings. Compared to existing frequency-division multiplexed training schemes, the proposed algorithm does not entail any additional bandwidth while with the advantage for system adaptive resource allocation.
IEEE LAN/MAN Standards Committee : IEEE 802.16e: air interface for fixed and mobile broadband wireless access systems. 2005.
3GPP TR 25.913 (V7.3 0) : Requirements for evolved UTRA (E-UTRA) and evolved UTRA N (E-UTRAN). 2006.
Giannakis GB, Tepedelenlioğlu C: Basis expansion models and diversity techniques for blind identification and equalization of time-varying channels. Proceedings of the IEEE 1998, 86(10):1969-1986. 10.1109/5.720248 CrossRef
Hou W-S, Chen B-S: ICI cancellation for OFDM communication systems in time-varying multipath fading channels. IEEE Transactions on Wireless Communications 2005, 4(5):2100-2110. CrossRef
Dai X: Optimal training design for linearly time-varying MIMO/OFDM channels modelled by a complex exponential basis expansion. IET Communications 2007, 1(5):945-953. 10.1049/iet-com:20045301 CrossRef
Ma X, Giannakis GB, Lu B: Block differential encoding for rapidly fading channels. IEEE Transactions on Communications 2004, 52(3):416-425. 10.1109/TCOMM.2004.823604 CrossRef
Tugnait JK, He S: Doubly-selective channel estimation using data-dependent superimposed training and exponential basis models. IEEE Transactions on Wireless Communications 2007, 6(11):3877-3883. CrossRef
Hung K-C, Lin DW: Optimal delay estimation for phase-rotated linearly interpolative channel estimation in OFDM and OFDMA systems. IEEE Signal Processing Letters 2008, 15: 349-352. CrossRef
Ghogho M, Swami A: Estimation of doubly-selective channels in block transmissions using data-dependent superimposed training. Proceedings of the European Signal Processing Conference (EUSIPCO '06), September 2006, Florence, Italy
Fertl P, Matz G: Multi-user channel estimation in OFDMA uplink systems based on irregular sampling and reduced pilot overhead. Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '07), April 2007, Honolulu, Hawaii, USA 3: 297-300.
Hayashi K, Sakai H: Uplink channel estimation for OFDMA system. Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '07), April 2007, Honolulu, Hawaii, USA 3: 285-288.
Zhou GT, Viberg M, McKelvey T: A first-order statistical method for channel estimation. IEEE Signal Processing Letters 2003, 10(3):57-60. 10.1109/LSP.2002.807864 CrossRef
Tugnait JK, Luo W: On channel estimation using superimposed training and first-order statistics. IEEE Communications Letters 2003, 7(9):413-415. 10.1109/LCOMM.2003.817325 CrossRef
Yang Q, Kwak KS: Superimposed-pilot-aided channel estimation for mobile OFDM. Electronics Letters 2006, 42(12):722-724. 10.1049/el:20060758 CrossRef
Chen N, Zhou GT: Superimposed training for OFDM: a peak-to-average power ratio analysis. IEEE Transactions on Signal Processing 2006, 54(6, part 1):2277-2287. CrossRef
Cui T, Tellambura C: Pilot symbols for channel estimation in OFDM systems. Proceedings of the IEEE Global Telecommunications Conference (GLOBECOM '05), November 2005, St. Louis, Mo, USA 4: 2229-2233.
Ghogho M, McLernon D, Alameda-Hernandez E, Swami A: Channel estimation and symbol detection for block transmission using data-dependent superimposed training. IEEE Signal Processing Letters 2005, 12(3):226-229. CrossRef
Liang T-J, Rave W, Fettweis G: Iterative joint channel estimation and decoding using superimposed pilots in OFDM-WLAN. Proceedings of the IEEE International Conference on Communications (ICC '06), July 2006, Istanbul, Turkey 7: 3140-3145.
Barhumi I, Leus G, Moonen M: Optimal training design for MIMO OFDM systems in mobile wireless channels. IEEE Transactions on Signal Processing 2003, 51(6):1615-1624. 10.1109/TSP.2003.811243 CrossRef
- Linearly Time-Varying Channel Estimation and Symbol Detection for OFDMA Uplink Using Superimposed Training
- Springer International Publishing
EURASIP Journal on Wireless Communications and Networking
Elektronische ISSN: 1687-1499
Neuer Inhalt/© ITandMEDIA, Best Practices für die Mitarbeiter-Partizipation in der Produktentwicklung/© astrosystem | stock.adobe.com